Forever Yours
by The Killer Bunny
Summary: Life isn't easy for Shiro, especially when a self-serving demon is pulling the strings. Part 3 of Lettersverse.
1. March 31, 2009

_This fic takes place in the same universe as **Sincerely** and **Until Next time**. It's our last installment for our "Lettersverse" that's relevant to the plot we've got going on. This installment won't be updated as often as the other two stories. It's more of a fill-in-the-blanks kind of thing. Considering that, it's kind of important to at least read up to chapter 29 in **Sincerely** in order to follow along with this chapter. We hope you enjoy it!_

* * *

_March 31, 2009_

* * *

"—you came at the perfect time too. These kids have had quite a day. How about we send them off while you and I discuss things?"

This was possibly Shiro's worst nightmare. Rin was never supposed to get anywhere near the True Cross Academy. He was never supposed to know of the Kurikara, much less open it. But there he was, standing in Mephisto's office being accepted as a student in the Academy.

And he had a tail.

"Rin." Shiro spoke sternly, glaring at Mephisto. "Go with Ryuuji-kun to his dorm. Spend the night there. I'll pick you up in the morning. I have to have a long talk with the Chairman about your future here."

For once, Rin didn't argue and Shiro was glad that he didn't. He waited, never taking his eyes off the demon before him until the two boys were gone from the room. He felt the quiet anger in him start to bubble over in his chest. Part of it was directed at Mephisto because he knew that the silver-tongued demon had something to do with the way things ended up. And then at himself, because he wasn't strong enough to handle this situation on his own.

"What in God's name are you playing at?" Shiro snapped through gritted teeth.

Mephisto's lips tilted up at the words. His gaze focused back on Shiro now that the two teens were gone.

"What do you mean?" the demon asked in an innocuous tone. Emerald-green eyes glinted with poorly hidden amusement.

"You know what I mean," Shiro growled, but he elaborated regardless. "Accepting Rin into the Academy! Do you know how much danger you're putting him in?"

"There were little other alternatives that we could have taken." Mephisto shrugged, undaunted by Shiro's anger. He plopped back down one of the seats and crossed his legs in front of him. "For all your precautions, you were too steadfast in the belief that he would never break the seal on the sword. Did you really think you could keep his existence hidden from the Vatican now that it has?"

"So your solution is to put him right under the Vatican's noses?" Shiro didn't move from his spot, glaring at how relaxed the demon seemed to be. But of course, why should he expect anything less?

"Naturally~!" Mephisto grinned up at his old friend. "What better way to flip the tables on them than by making him a vital part of the very organization which hunts him? Make him useful to them, and they won't dare to dispose of him—no matter how much they loathe what he truly is."

From an objective point of view, from his paladin side, it was a good plan. Hell, it was more than a good plan. It was all they got. But knowing that Rin was the one that was going to be at the center of it all… "That's too risky." Shiro shook his head. "You're betting my son's life in this. How can you guarantee that they won't just say fuck it and kill him anyway?"

"Guarantee?" Mephisto repeated the word as if it was unfamiliar to him. His lips twitched slightly as he shot the other a hooded look. "I never make promises I don't plan to keep… but it takes more than mere friendship to offer such a guarantee."

As usual, the long-standing offer to grant the paladin's wishes was silently extended to him.

"Whether he survives what is to come remains as much of a mystery to me as it is to you." The demon shrugged lightly. "More importantly, unless you plan on making another bargain, your part in molding the boy's life is over. As per our agreement, his fate is in my hands now… and his own, I suppose. He's the one that chose this path himself without any prompting from me." Mephisto looked pleased by his own words; he always did when something managed to catch him by surprise.

Shiro tossed a bitter smirk to the side. Demons and their deals. Still, the words stung. The mere thought of Rin being removed from his care was something he loathed. He wouldn't allow it to happen, bargain or not.

"I think I'll hold onto my soul for right now." He offered a malicious grin to the Chairman. "As collateral." Shiro walked over to Mephisto, his steps as calculated as his words. "I'm not willing to go all in with such a dangerous game. I hope you understand."

It was always a game with them. Always. Whether it was a game of chess, of quick wits and intellect, or a game of poker, of bluffs, lies, and treachery, it was always a game. It was how Mephisto liked it and Shiro was well aware. Sometimes he wondered if he liked it just as much as the demon. But this time, Rin was in the middle and all their previous games seemed like practice. This was it. Shiro was holding a possibly game-breaking hand and he'd be sure to play it carefully.

The demon observed as Shiro carefully approached him, but when gray-haired man was close enough to touch, Mephisto didn't reach out. Instead, he smiled.

"It's nothing less than what I had expected."

It was a fond voice, the low, hot murmur approving. Mephisto waved a hand in front of him, dismissing the matter in the same way he would dismiss a menu.

"Shall we move onto the next topic, then?" Emerald-green eyes focused on the dark eyes hidden behind the barrier of his glasses. The paladin's thoughts remained concealed to the demon's penetrating gaze.

"He can't stay with the other kids." The next topic seemed obvious enough. Shiro crossed his arms. "As much as it pains me to say, I don't know how Rin's powers are going to affect him now. I know he's going to do his best to control them but as of right now, he's a bit of a wild card. I don't want him to hurt himself or anyone else."

Shiro sat down on the coffee table in front of Mephisto and met his gaze, keeping that eye contact. "So where are you going to put us?"

"Hmm…" The question made Mephisto pressed a gloved finger to his lips. His expression turned contemplative. "Where, indeed…?" He stroked his beard twice before his eyes lit up. Snapping his fingers caused a map of the Academy to appear with a purple marker alongside it.

"Ah, I know the perfect place~!" After snatching the items off midair, he scribbled on the map and then tapped his finger to the place he had circled as he showed it to Shiro. "The old boys' dorms are unused now that we have made renovations. I'll put a hold on demolishing the place for you for as long as the boy studies here. What do you think~?"

Shiro leaned in to inspect the spot. "Is it inhabitable?" The paladin raised an eyebrow at his friend. "The ceiling isn't going to collapse on us, right?"

Mephisto shot Shiro an insulted look. "A little more faith would be appreciated!" He pulled the map away and rolled it up as he continued. "The only thing you have to worry about is cleaning. I'll have the water and electricity working again by tomorrow. Of course, I'll be taking those costs out of your paycheck," he added with a devilish grin. "The rest is in your hands."

Shiro stared at Mephisto, his lips still marred by that frown. Of course, his paycheck. But still, he knew that this was the best he was going to get out of Mephisto without offering a certain something of his in return. "Fine." He stood up and pushed up his glasses. "I'll have everything moved in by the morning."

"Excellent!" Mephisto followed the other to his feet and handed over the map, placing it in Shiro's hand. If his fingers lingered on the paladin's skin a little longer than propriety dictated, his expression didn't betray it. "Last thing, then. I can easily enroll him discreetly as a last minute entrant, but it's best to keep everything official. I'll arrange it so he can make up the entrance exams before sorting him into the high school classes." The demon grinned. "He'll have to do his best to brush up on his studies. The most I can give him is until the day before classes begin, agreed?"

Shiro held the map in a loose fist. "Agreed." He nodded. "It's best for him if he goes back to school anyway." He rubbed his forehead and frowned. "I have preparations to make."

Shiro headed towards the door but he stopped short before placing his hand on the knob. "Mephisto." He spoke without turning to look. "If you put either of my sons in danger, I promise you that I won't be as compliant as I've been in the past. This is an entirely different matter from our usual games. Do you understand?"

"So protective of your little lion cubs. You should worry less about me, and more about yourself, Shiro." There was a slight pause. Mephisto's voice showed no hint of concern, but there was something different about the way he was staring at Shiro's back, at the faint hint of skin that lingered between his hairline and the brim of his cassock. "You're looking awfully pale," he murmured.

Shiro smirked tightly and glanced at the Chairman over his shoulder. "Worried about me?" His tone held that usual teasing tone, but the light didn't reach his eyes.

"Aren't I always?"

The purple-haired demon gave a slight shrug. His lips tilted upwards as he caught the paladin's glance.

"You'll be of no use to anyone if you die, Shiro. Do your best not to let your guard down," he cautioned.

The paladin gave a soft chuckle and he turned the doorknob. "Well, don't get your panties in a bunch. I've held out for this long. I have no intention of dying any time soon." Shiro walked out of the office, his step as determined and steadfast as always.

When the door closed behind him, Mephisto's light smile turned as dark and as somber as the bags under his eyes. Green eyes stared at the empty space where Shiro had been standing. The reassurance that he would see the gray-haired man again beyond this day made a choir of triumph throb in his chest.

"I have no intention of letting you die either, Shiro. Not this time. Not for a long while," he murmured to himself. The look of satisfaction on his face was one that didn't fade for the rest of the night.


	2. April 1, 2009 (Midnight)

"Ah~"

Mephisto watched as the bright red digits on his monitor turned, signaling the start of the new day. The sky was still dark outside, of course—after all, it was merely midnight. And yet, it was this moment that he had been waiting for all day.

At that very second, his servant, Belial, promptly entered the room. Mephisto glanced at him from his desk expectantly.

"Anything to report?"

"Everything is in order, Sir Pheles."

"Excellent! That will be all then!"

Belial bowed and left the room as quietly as he had entered it.

Mephisto's face lit up. Shiro was still alive.

He had truly succeeded.

Mephisto had been sure of his victory hours ago but this was the final nail on the coffin—the final confirmation that assured him everything had gone according to plan. If before a choir had throbbed in his chest, now an orchestra resonated loudly.

"I really have outdone myself," he murmured quietly. He got up to his feet and strode to stare out the tall windows that faced the courtyard. True Cross Academy was alit with life. Though most of its residents were already fast asleep, many others still continued their daily activities. Shiro, Mephisto supposed, was still up, preparing for the upcoming days.

"Yes, this is exactly how things should be…"

The quick grin on Mephisto's lips was faintly reflected on the window. The vivid twinkle on the depths of his green eyes seemed to glow brightly as he stared beyond the glass surface, across the screen.

Mephisto began to speak.

"It is my humble opinion that life's twists and turns are the necessary spice that keeps the tedious repetition of human life from getting stale. When confronted with these situations, the choices people make are, for the most part, the result of random factors—they are decisions made in a split second and they can easily change with the slightest nudge in the right—or the wrong—direction."

There was barely a pause between the words. Mephisto's voice was calm, his tone eloquent and deliberate.

"I prefer not to interfere with these trivial matters for the most part. It is much more interesting to keep watch from afar and observe as humans struggle forward, battling out or seeking to indulge their desires."

Mephisto's expression twisted at his own words. The light in his eyes sharpened as an indulgent smirk crossed his lips.

"But of course, there are times when even a demon such as myself seeks to interfere. I am, after all, a pleasure-seeker and a hell-raiser above all else and I hold none of the inhibitions humans claim to possess."

The quiet chuckle that escaped the demon's lips reverberated across the room. Mephisto turned away from the window. His feet led him to stand before a long thin table at the side of the room. Gloved fingers gingerly circumvented a large flower vase and plucked up an empty box of cigarettes that had been resting in this place for over a decade now. The sight of it was nostalgic. As much as the demon detested the smell of smoke, faint as it was, this was a reminder of older, simpler times.

Mephisto was not a being that was prone to dwell on the past, but that man was always an exception.

"The matter in this case was the death of my old friend, Fujimoto Shiro," he continued to explain, smiling. "It was fact that his death was an event that Fate steered to happen. I saw proof of it myself fifteen years ago.

"Now, I would like to assure you that it was not a matter I purposely looked into. Dreams, for a being with the abilities I possess, can at times be both a blessing and a curse. It was on a night fifteen years ago, a few months after Shiro had adopted the Okumura twins, that I stumbled upon a dream that predicted his death."

After putting the cigarette box down back where it belonged, Mephisto closed his eyes and took a small breath.

"The vision was a surprise, to say the least," he confessed. "To this day, I wonder if I was glad to have seen it or not. Had I not, the idea of Shiro dying wouldn't have been such an unwelcome thought. To think that Father would snatch him away from my hands in that manner, to think that Shiro would give in after all his years of staying strong against him… It surprised me," he said, his voice a low murmur, "and I do love surprises~"

Mephisto's eyes slowly peered open. The dull gleam in his eyes did not match the light lilt of his voice. His lips twitched and then fell into a frown.

"But having seen that dream spoiled the surprise, and I no longer cared for the idea of having Shiro taken away—but don't get the wrong impression now." Mephisto wagged his finger, turning his penetrating gaze back to the screen. "I won't deny that there is a special relationship between that man and I, but I certainly did not save him for a ridiculous concept such as "love"! Who exactly do you take me for?"

He scoffed; waved a hand before him as if to dismiss the idea.

"Can anyone guess why I interfered?" he asked, and let the question hang in the air.

There was a beat of silence. Then, Mephisto smiled, the pointed edge of his fangs peeking through the gap of his lips.

"The correct answer is simply: "I wanted to see what that man would do next.""

Mephisto looked pleased with himself. The reactions of his audience didn't faze him in the slightest.

"Shiro is not a unique man… and yet, he's managed to catch me off-guard more than most. He's a being worthy of my time and someone I wanted to play with for just a little longer," he explained with a slight shrug.

"And so, I let myself dream. I caught glimpses of the future, all of them faint, all of them different. Shiro's death was not a set event, but it was one that happened often. At first I thought the best solution was to get rid of those two, but…"

A snap of his fingers caused the Mephisto's office to vanish. The purple-haired demon found himself standing in the grounds of the Southern Cross Boys' Monastery. His transient presence was inconsequential to the moment that now existed outside of time.

Shiro stood immobile in front of a pair of graves, his face ashen and his hands limp at his side.

"This option had undesirable results." Mephisto let out a long sigh. He shook his head in disappointment. "In this future, Shiro's carelessness caused the Vatican to notice the existence of his adopted sons. Okumura Rin lost control of his powers, and fearing the potential threat that the younger brother posed, they mercilessly eliminated the two boys while they were still children."

* * *

_"They were just **children**…" Shiro hissed angrily, the lines of his face etched with bitterness. "Rin could have still… There were other options they could have taken! And Yukio…! I should've…" The man's breath hitched as the memory of his sons' death surfaced and replayed in his mind. His teeth clenched tightly but the composure the priest tried to maintain crumbled within seconds._

_He looked defeated. Slumped on the couch in Mephisto's office, Shiro's eyes were dull and his complexion was drained by his sorrow. It was an appearance that wouldn't change for the rest of his walking days—and those days were numbered. Weeks would pass before he went to trial, lost his position, and ultimately his will to continue on._

* * *

"Poor Shiro's heart couldn't take the loss. I might have kept him alive, but inside… he'd become worthless. Nothing more than a broken toy." Mephisto grimaced at his own words. "Playing with him wasn't fun anymore." A snap of his fingers caused the scenery to quickly change.

"Then, there was this future…"

* * *

_"This isn't over!" Shiro growled, rage burning in his voice. "I won't let that bastard snatch Rin away so easily. We're getting him back!" Shiro's expression brooked no argument. It was decisive and resolute. When he glanced at Yukio, the boy looked younger than ever, pale and worried, but the sight of his somber son did nothing to calm the turbulent feelings growing in his chest._

_Shiro turned to Mephisto and stalked towards him, curling his fingers tightly around the pink cravat on the demon's neck._

_"There's got to be something I can do. Help me, Mephisto, or I swear to God, things won't end well for you."_

* * *

"It was a deliciously heated threat. There was a lot of potential to this path. As you may have guessed, Father managed to get his hands on his precious son, leaving Shiro alone with young Yukio at his side to deal with the loss. There was such fire burning in his eyes this time. Shiro was incensed, he grew obsessed—it was a beautiful sight… but he grew too careless. In every variation of the future that followed this path, Shiro ended up dying in his foolhardy effort to get Rin back."

Mephisto let out another sigh.

"He's as difficult and as unpredictable as ever. I was quite annoyed at Shiro's insistence to die. It was starting to get ridiculous."

While shaking his head, the purple-haired demon explained his frustration. "He was never the type to give up so easily before adopting those boys—and I knew that tenacity was still inside of him. He just needed the right opportunity…And so, I considered lending him a helping hand. I pondered then, what would happen if he were to survive Father's possession?"

Mephisto snapped his fingers, and once again, the scenery changed. This time, Shiro was not in Mephisto's office. Instead, he was lying on a bed in a hospital room. Rin and Yukio were standing at their father's side.

* * *

_"Thank god…" Rin's voice hitched. He stared at the unconscious body of his father and couldn't help but to shoot his brother a wavering smile._

_"I told you it was gonna be fine. There's no way the old man would ever die on us."_

* * *

"I thought this would be it—Shiro was bound to wake up. He was in a critical condition but on the road to recovery. But then…"

* * *

_"This is your fault," Yukio whispered as he stared at their father's bloodless, still expression. He looked away as fear seized his chest. His fists tightened._

_"What?"_

_Yukio's eyes were hidden from sight as he stared at the floor, his bangs covering his face. The glare in his glasses hid his true expression from view when he looked up again. His lips were set into a thin, firm line as he looked at his brother._

_"If it wasn't for you, none of this would have happened. I know—I know Father tried to protect you. I know you didn't know better. You were my brother, and I wanted to protect you from all of this… but in the end, you turned out to be nothing but a monster. I'm sorry, but I know that this is for the best. Please understand."_

_Rin look stricken at the words. He stared wordlessly as Yukio reached behind him and took out a gun._

_"Yukio! W-Wait…!"_

_Pale fingers wrapped around the trigger and shook slightly, but in the end, Yukio went through with it. The noise was so deafening, Shiro awoke from his deep slumber just in time to see Rin's body crash to the ground._

_"Yukio… what did you… do…?"_

_"…My job."_

* * *

"I saw that it wasn't enough," Mephisto finished in an annoyed tone. With another snap of his fingers, the demon found himself back in his own time, back in his office. He casually made his way to his desk and plopped down on his seat.

"That's when I realized that the real problem here wasn't Shiro at all. It was those boys…"

Mephisto picked up the warm cup of tea that was waiting for him. He took a brief sip before placing it back down. Inches away from the saucer were a pair of letters that he spared a small glance to. The words "_Forever Yours" _were neatly written at the bottom with an exaggeratedly delicate calligraphy. The same words peeked out from the letter underneath in a handwriting that resembled chicken scratch. Mephisto smiled at the sight of them.

"It became clear to me then that those boys were unstable. Shiro did his best by them, but humans require so much more than the kind words of a father to be healthily nurtured, especially those two. It was not easy for them to grow up, not when they were so isolated, so feared—so afraid.

"And so, I figured out the best way to give them the emotional stability they needed."

* * *

_"You want to make our students start exchanging letters with students from another city? What a wonderful idea! Yes, let's make it a tradition from today on."_

* * *

"It was all too easy to arrange those boys with a suitable partner that would help them overcome that inconvenient lack of confidence they had in themselves and their sole dependence on Shiro. They reacted positively, and much to my delight, everything went according to plan—though I was certainly not expecting things to turn out this well!"

Mephisto's eyelids dropped and he smiled at the memory of Rin declaring his desire to becoming an exorcist, of Shiro's shocked face and accusing eyes. Eyes that would continue to have that fire lit in them. Eyes that would continue to challenge him for much longer than they were meant to—

"Hmm?" Mephisto's trail of thought halted for a moment. "Will there be a cost?" His pointed ear perked at the question. "How very astute of you to ask! Why, there are many literary works that warn humans of the risks of changing the past. Keep in mind that I did nothing of the sort though. I merely nudged the present to a future of my liking."

Nevertheless, Mephisto nodded, acknowledging the point that had been brought up.

"Still, we must wonder… are these warnings truth or are they merely fiction?"

Despite proposing the question, the demon shrugged lightly in reply.

"Even if I had the answer—and I'm afraid I do not—I'd advise you not to press me for it. As things stand, the events that follow beyond today will be as much as a surprise to me as it will be to you.

"I hope you are as prepared as I am, for the path ahead of us will surely be one hell of a ride!" he exclaimed passionately, his lips stretched wide into a toothy, sharp grin.

His expression remained like that even as he picked up his tea again. Mephisto took another short sip, thoroughly savoring the taste of his victory and the anticipation of what was to come.

When he put the cup back down, the green depths of his eyes were glowing luminously.

"Well then, with that said, I'll ask you to keep any further question to yourselves. Read on and enjoy, will you?

"_Auf wiedersehen~__"_


End file.
